This invention relates to a hose clamp used particularly for the purpose of clamping a rubber hose, for example.
A hose clamp which has found extensive utility is disclosed in U.S. Pat. No. 4,305,179 and constructed by forming a clamp body in an annular shape and bending the opposite terminal pars of the clamp body in a mutually crossing manner, thereby clamping a rubber hose, for example, by virtue of the clamping resilient force generated by the clamp body. Various techniques have been proposed concerning the hose clamp.
In almost all of the conventional hose clamps of this type, since the mutually crossing opposite terminal parts thereof are raised upright to a large height outwardly in the radial direction, persons engaging in the work of putting such clamps on a rubber hose often suffer from unforeseen accidents. Even after these hose clamps have been put on rubber hoses, they are liable to bring about similar accidents.
An improved hose clamp having the opposite terminal parts of its clamp body bent upright in a mutually crossing manner to a decreased height has been disclosed in Japanese Patent Public Disclosure No. 57-103920. This prior art hose clamp is molded from one resilient Metallic sheet and formed by looping the metallic sheet into an annular clamp body, stamping a first terminal part of the annular clamp body into a lock wall which has a part extending in the radial direction and another part extending in the tangential direction and consequently assuming a substantially L-shaped cross section, perforating an opening in the radially extending part of the lock wall, and punching a guide groove so as to extend continuously from the opening through the clamp body. A second terminal part of the clamp body is given a width small enough to move inside the opening and the guide groove and has the leading end thereof bent upwardly. Thus, the bent leading end of the second terminal part can be joined to the lock wall of the first terminal part.
In the prior art hose clamp, therefore, the union of the curved leading end of the second terminal part with the lock wall of the first terminal part allows the clamp body to be retained in a radially expanded state and, at the same time, gives rise to an insertion space between the second terminal part and the tangentially extending part of the lock wall.
Owing to this construction, the actual use of the prior art hose clamp is attained by placing the curved leading end of the second terminal part into engagement with the lock wall of the first terminal part, thereby setting the clamp body in a radially expanded state, inserting the clamp body around a rubber hose, then inserting the leading end of such a tool as a slotted screwdriver into the insertion space formed between the second terminal part and the tangentially extending part of the lock wall, jerking the tangentially extending part of the lock wall, jerking the tool and depressing the second terminal part down, thereby releasing the bent leading end of the second terminal part from the union thereof with the lock wall and allowing the second terminal part to move through the opening in the lock wall to the inside of the guide groove by virtue of the resilient force of the clamp body itself and further permitting the clamp body to radially contract instantaneously, with the result that the rubber hose is automatically clamped.
The prior art hose clamp has an advantage that the work of clamping a rubber hose is simple because the clamp body automatically acquires its radially contracted state by merely disengaging the curved leading end of the second terminal part from the lock wall by the use of such a tool as a slotted screwdriver as described above. Actually, on account of the construction, the release of the curved leading end of the second terminal part from the union with the lock wall can be attained only when the leading end to the tool is inserted in the direction of the lateral side of the clamp body into the insertion hole formed between the second terminal part and the tangentially extending part of the lock wall. This release of the curved leading end cannot be attained in any other direction. Therefore, the prior art hose clamp has a disadvantage that owing to the restriction imposed by the directionality of the tool to be used, the hose clamp itself, depending on the condition of its attachment to the rubber hose, defies insertion of the tool to impair its workability.
Where the prior art hose clamp must be removed from the rubber hose for the purpose of reuse, since the part of the hose clamp which can be nipped with such a tool as pliers is short, it is extremely difficult for the clamp body to be spread out against the resilient force of its own and set into a radially expanded state again.